Clinical Focus

  • Emergency Medicine
  • Health Care Management
  • Emergency Department operations
  • Digital Health
  • Quality Improvement

Academic Appointments

Administrative Appointments

  • Vice Chair, Clinical Affairs & Quality, Stanford University School of Medicine (2017 - Present)
  • Fellowship Director, EM Administration Fellowship (2015 - Present)
  • Medical Director, Emergency Medicine (2014 - 2017)

Boards, Advisory Committees, Professional Organizations

  • Member, Society of Academic Emergency Medicine Fellowship Committee (2016 - Present)
  • Fellow, American College of Emergency Physicians (2008 - Present)
  • Board Certified, American Board of Emergency Medicine (2006 - Present)
  • Member, American College of Emergency Physicians (2006 - Present)

Professional Education

  • Medical Education:UCLA David Geffen School Of Medicine Registrar (2002) CA
  • Residency:Beth Israel Deaconess Medical Center (2005) MA
  • Internship:Beth Israel Deaconess Medical Center (2003) MA
  • MBA, Anderson School of Management at UCLA (2002)
  • BS, Stanford University, Biology, with Honors (1995)

Research & Scholarship

Current Research and Scholarly Interests

Emergency Department process improvement
ED innovations



All Publications

  • Introduction of a Horizontal and Vertical Split Flow Model of Emergency Department Patients as a Response to Overcrowding. Journal of emergency nursing: JEN : official publication of the Emergency Department Nurses Association Wallingford, G., Joshi, N., Callagy, P., Stone, J., Brown, I., Shen, S. 2017


    ED overcrowding is an issue that is affecting every emergency department and every hospital. The inability to maintain patient flow into and out of the emergency department paralyzes the ability to provide effective and timely patient care. Many solutions have been proposed on how to mitigate the effects of ED overcrowding. Solutions involve either hospital-wide initiatives or ED-based solutions. In this article, the authors seek to describe and provide metrics for a patient flow methodology that targets ESI 3 patients in a vertical flow model.In the Stanford Emergency Department, a vertical flow model was created from existing ED space by removing fold-down horizontal stretchers and replacing them with multiple chairs that allowed for assessment and medical management in an upright sitting position. The model was launched and sustained through frequent interdisciplinary huddles, detailed inclusion and exclusion criteria, scripted text on how to promote the flow model to patients, and close analytics of metrics. Metrics for success included patient length of stay (LOS) for those triaged to the vertical flow area compared with ESI 3 patients triaged to the traditional emergency department as a comparison group. The secondary outcome is the total number of patients seen in the vertical flow area. This was a 6-month-September 2014, to February 2015-retrospective pre- and postintervention study that examined LOS as a marker for effective launch and implementation of a vertical patient workflow model.The patients triaged to the vertical flow area in the study period tended to be younger than in the control period (43 years versus 52 years, P = 0.00). There was a significant decrease in our primary end point: the total LOS for ESI 3 patients triaged to the vertical flow area (270 minutes versus 384 minutes, P = 0.00).Implementation of a vertical patient flow strategy can decrease LOS for the vertical ESI 3 patients based upon the inclusion and exclusion criteria. Furthermore, this is accomplished with minimal financial investment within the physical constraints of an existing emergency department.

    View details for DOI 10.1016/j.jen.2017.10.017

    View details for PubMedID 29169818

  • Lean Manufacturing Improves Emergency Department Throughput and Patient Satisfaction. journal of nursing administration Kane, M., Chui, K., Rimicci, J., Callagy, P., Hereford, J., Shen, S., Norris, R., Pickham, D. 2015; 45 (9): 429-434


    A multidisciplinary team led by nursing leadership and physicians developed a plan to meet increasing demand and improve the patient experience in the ED without expanding the department's current resources. The approach included Lean tools and engaged frontline staff and physicians. Applying Lean management principles resulted in quicker service, improved patient satisfaction, increased capacity, and reduced resource utilization. Incorporating continuous daily management is necessary for sustainment of continuous improvement activities.

    View details for DOI 10.1097/NNA.0000000000000228

    View details for PubMedID 26252725

  • Arthrocentesis of the Knee (Videos in Clinical Medicine) Arthrocentesis of the Knee Thomsen, T. W., Shen, S., et al 2006; e19: 354

    View details for DOI 10.1056/NEJMvcm051914